Apparatus, kit, and method for a cooling system

ABSTRACT

Various methods and systems are provided for an apparatus forming at least a portion of a cooling circuit for a fluid source. In one example, the apparatus includes a first radiator system having a parallel flow path configuration, a second radiator system having a series flow path configuration, and at least one shutter system for adjusting airflow to one or more of the first radiator system or the second radiator system. The apparatus further includes a controller configured to adjust operation of the shutter system responsive to an operating condition.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 61/429,129 filed Jan. 1, 2011, the disclosure of which is incorporated by reference in its entirety for all purposes.

FIELD

Embodiments of the subject matter disclosed herein relate to cooling systems for engines such as internal combustion engines.

BACKGROUND

Vehicles, such as rail vehicles, may be powered by one or more engines that maintain a suitable operating temperature by releasing excess heat to ambient air surrounding the vehicle. The excess heat may be conducted away from the one or more engines via a recirculating cooling fluid, such as water or coolant, and dissipated into the ambient air via one or more radiators. The cooling fluid may draw heat from various engine components or systems which include charge-air intercoolers, cooling jackets, oil coolers, and the like. The rate of cooling provided to each of the engine components partly controls their operating temperatures which, in turn, may affect engine performance and emissions.

As an example, a level of nitrogen oxide (NO_(x)) emissions from the engine may be related to a manifold air temperature, with lower manifold air temperatures enabling lower NO_(x) emissions. In some examples, providing cooling fluid of a relatively low temperature to the charge-air intercoolers may decrease NO_(x) emissions. Further, providing cooling fluid of a somewhat higher temperature to oil coolers and cooling jackets may reduce over-cooling of the engine, thereby increasing efficiency of the system. In such an approach, however, under various conditions such as low ambient air temperature, the radiators may provide too much cooling. As such, the radiators may be drained under certain operating conditions resulting in thermal shock to the radiators and increased radiator degradation.

BRIEF DESCRIPTION

In one embodiment, an apparatus forming at least a portion of a cooling circuit for a fluid source includes a first radiator system having a parallel flow path configuration and a second radiator system having a series flow path configuration. The apparatus further includes at least one shutter system for adjusting airflow to one or more of the first radiator system and/or the second radiator system, and a controller configured to adjust operation of the shutter system responsive to an operating condition.

The series flow path configuration of the second radiator may have a zigzag shape, for example. In such a configuration, an effective length of the radiator is increased. In this way, greater cooling of the fluid occurs in the second radiator system. In some examples, cooled fluid from the second radiator system may be routed to a charge-air intercooler disposed in an intake passage of an engine such that a manifold air temperature may be further reduced, resulting in decreased NO_(x) emissions in an exhaust stream of the engine, for example. Further, the shutter system may be operated to close in order to hold in heat when less cooling is desired, such as when an ambient temperature (e.g., temperature external to the vehicle) is relatively low and an engine cooling fluid temperature is less than a threshold temperature. In this manner, cooling fluid may remain in the first and second radiator systems during low temperature periods and thermal shock of the radiator systems may be reduced.

It should be understood that the brief description above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:

FIG. 1 shows a schematic diagram of a vehicle with a cooling system, according to an embodiment of the invention.

FIG. 2 shows a schematic diagram of aspects of a modified radiator system according to an embodiment of the invention.

FIG. 3 shows a schematic diagram of an air flow control system for a cooling system, according to an embodiment of the invention.

FIG. 4 shows a schematic diagram of an air flow control system for a cooling system, according to an embodiment of the invention.

FIG. 5 shows a perspective view of an air flow control system according to an embodiment of the invention.

FIG. 6 shows an exemplary retrofit kit according to an embodiment of the invention.

FIG. 7 shows a flow chart illustrating a method for operating a modified cooling system, according to an embodiment of the invention.

DETAILED DESCRIPTION

The following description relates to various embodiments of an apparatus, a kit for retrofitting an engine system having a cooling system, and methods for operating an engine system (e.g., the engine system having a modified cooling system). In one exemplary embodiment, an apparatus which forms at least a portion of a cooling circuit for a fluid source includes a first radiator system having a parallel flow path configuration and a second radiator system having a series flow path configuration. The apparatus further includes at least one shutter system for adjusting airflow to one or more of the first radiator system or the second radiator system, and a controller configured to adjust operation of the at least one shutter system responsive to an operating condition. In another example embodiment, a retrofit kit may be applied to a cooling system such that the modified cooling system includes such an apparatus. The series flow path configuration has a longer length such that a dwell time (e.g., duration the cooling fluid is in the radiator system) of the cooling fluid within the second radiator system is longer than the dwell time of the cooling fluid within the first radiator system. In this manner, the cooling fluid may exit the second radiator system with a relatively lower temperature than the cooling fluid that exits the first radiator system. Further, the at least one shutter system may be controlled based on an engine cooling fluid temperature. For example, in the case of first and second shutter systems, shutters of the first and second shutter systems may be closed when the engine cooling fluid temperature falls below a threshold temperature, to prevent overcooling of the engine system. As such, the radiators may be fully flooded such that cooling fluid remains in the first and second radiator systems throughout engine operation even during low temperature operation.

In one embodiment, the cooling system may be coupled to an engine in a vehicle. A locomotive system is used to exemplify one of the types of vehicles having engines to which the cooling system may be attached. Other types of vehicles may include on-highway vehicles and off-highway vehicles other than locomotives or other rail vehicles, such as mining equipment and marine vessels. Other embodiments of the invention may be used for cooling systems that are coupled to stationary engines. The engine may be a diesel engine, or may combust another fuel or combination of fuels. Such alternative fuels may include gasoline, kerosene, biodiesel, natural gas, and ethanol. Suitable engines may use compression ignition and/or spark ignition.

FIG. 1 shows a block diagram of an exemplary embodiment of a vehicle system 100, herein depicted as a locomotive or other rail vehicle 106 configured to run on a rail 102 via a plurality of wheels 112. As depicted, the rail vehicle 106 includes an engine system with an engine 104, such as an internal combustion engine.

A cooling fluid is stored in a cooling fluid reservoir 114. As used herein, “cooling fluid” refers to a thermal transport liquid or semi-liquid material. Examples of suitable cooling fluids include water, glycols, salt solutions, alcohols, and mixtures of two or more of the foregoing. In some embodiments, more exotic materials and/or performance affecting additives are contemplated, to include corrosion resistors, defoamers, anti-sludge agents, detergents, anti-gelling agents, biocidal agents, leak preventers (such as silicates) or locators (such as dye), anti-freezing agents (such as the above mentioned glycols and alcohols), and the like. As depicted in FIG. 1, the cooling fluid flows from the cooling fluid reservoir 114 to an oil cooler 116. The oil cooler 116 may be a liquid-to-liquid heat exchanger which cools the engine oil via heat exchange with the cooling liquid. Oil may be pumped from the oil cooler 116 to the engine 104, and from the engine to the oil cooler as needed.

A pump 118 pumps the cooling fluid from the oil cooler 116 and divides the cooling fluid flow. A first portion 119 of the cooling fluid is directed from the pump 118 to the engine 104 where it circulates through cooling jackets (not shown) surrounding cylinders (not shown) of the engine 104 and absorbs waste heat from the engine 104. The first portion of the cooling fluid is then directed to a first radiator system 120, e.g., a first bank of radiators, which includes (in this embodiment) three radiators. As depicted in FIG. 1, the first radiator system 120 has a parallel flow path configuration in which fluid flow through the three radiators occurs in parallel. For example, the cooling fluid enters the first radiator system 120 and a different portion of the cooling fluid flow flows through each radiator in the same direction. The first radiator system will be described in greater detail below with reference to FIG. 2. The cooling fluid is cooled as it exchanges heat with air as it passes through the first radiator system 120. The cooled first portion of cooling fluid exits the first radiator system 120 and flows back to the cooling fluid reservoir 114.

A second portion 123 of the cooling fluid is pumped via the pump 118 to a second radiator system 124, e.g., a second bank of radiators, which includes three radiators (in this embodiment). As depicted in FIG. 1, the second radiator system 124 has a series flow path configuration in which fluid flow through the three radiators occurs in series. For example, the cooling fluid enters the second radiator system 124 and substantially all of the cooling fluid flows through each of the three radiators in a zigzag pattern. In this manner, a flow speed of the cooling fluid is maintained while cooling of the cooling fluid is increased. For example, because the cooling fluid flows in a zigzag pattern, an effective length of the second radiator system 124 is increased, as compared to the first radiator system 120. As such, the dwell time of the cooling fluid within the second radiator system 124 increases, thereby increasing cooling of the cooling fluid as is flows through the second radiator system 124. The second radiator system is described in greater detail below with reference to FIG. 2.

As depicted, the first and second radiator systems 120 and 124 are separate and distinct. For example, the first and second radiator systems 120 and 124 may be located on different side of the vehicle 106. Further, each system comprises plural respective distinct radiator bodies, the radiator systems are fluidly decoupled (e.g., the first portion 119 of cooling fluid only flows through the first radiator system 120 and not through the second radiator system 124 and the second portion 123 of cooling fluid only flows through the second radiator system 124 and not through the first radiator system 120), and the radiator systems are each defined by one or more outer radiator body walls, with the systems having no such out radiator body walls in common.

Once the second portion of cooling fluid has passed through each of the radiators of the second radiator system 124, the cooling fluid exits the second radiator system and flows to one or more charge-air intercoolers 128 disposed in an intake passage of the engine to provide cooling to the charge-air in the intake passage. The second portion of cooling fluid exits the one or more intercoolers 128 and flows back to the cooling fluid reservoir 114.

The rail vehicle 106 further includes a controller 130 to control various components related to the vehicle system 100. In one example, the controller 130 includes a computer control system such as an electronic control system. The controller 130 further includes computer readable storage media (not shown) including code for enabling on-board monitoring and control of rail vehicle operation. The controller 130, while overseeing control and management of the vehicle system 100, may be configured to receive signals from a variety of engine sensors in order to determine operating parameters and operating conditions, and correspondingly adjust various engine actuators to control operation of the rail vehicle 106. For example, the controller 130 may receive signals from various engine sensors including, but not limited to, engine speed, engine load, ambient temperature (e.g., temperature external to the vehicle), cooling fluid temperature, manifold air temperature, altitude (or ambient air pressure), and the like. In some examples, the vehicle system 100 may include a plurality of manifold air temperature sensors, each of which disposed in or proximate to (e.g., immediately upstream of) a distinct manifold. Correspondingly, the controller 130 may control the vehicle system 100 by sending commands to various components such as traction motors, alternator, cylinder valves, throttle, or the like.

In one embodiment, as described below with reference to FIG. 7, the controller 130 may be configured to receive signals indicating ambient air temperature from one or more ambient air temperature sensors. In response to the signals (e.g., output from the one or more sensors), the controller 130 may be configured to send a signal to an actuator 132 to control opening of a first shutter system 122 and a second shutter system 126, the first shutter system 122 in thermal communication with the first radiator system 120 and the second shutter system 126 in thermal communication with the second radiator system 124. As an example, the controller 130 may signal the actuator 132 to close the first shutter system 122 and the second shutter system 126 in response to a measured ambient air temperature that is less than a threshold temperature (e.g., a designated or otherwise established threshold temperature). In this way, a temperature of the vehicle system 100 may be maintained when the ambient air temperature is relatively low. The first and second shutter systems will be described in greater detail with reference to FIGS. 3-5.

Continuing to FIG. 2, aspects of a modified radiator system 200 are shown. Specifically, two banks of radiators are shown: a first bank 202 of a first radiator system (such as first radiator system 120 described above) disposed on a first side of a rail vehicle, comprising first bank radiators 206, 208, and 210, and a second bank 204 of a second radiator system (such as second radiator system 124 described above) disposed on a second side of a rail vehicle, comprising second bank radiators 212, 214, and 216. In some examples, when a rail vehicle in which the radiator system 200 is disposed is viewed from the front, the first bank 202 may be on the right side of the rail vehicle, and the second bank 204 may be on the left side of the rail vehicle. Further, in some rail vehicles, the first bank 202 side is the same as the ‘operator side.’

Each of the first bank 202 and second bank 204 radiators is a liquid-air heat exchanger in which the transfer of heat from the cooling fluid to the ambient air is assisted by forced convection of the ambient air. Accordingly, the first bank 202 radiators and the second bank 204 radiators may include one or more air impellers (e.g., fans, shown in FIGS. 3-4). The air impellers may be configured to provide a substantially equal air flow to each of the first bank 202 and second bank 204 radiators. In some configurations, each of the first bank 202 and second bank 204 radiators may be a single-pass water-to-air heat exchanger having independent, interior-facing and exterior-facing header tanks. Thus, FIG. 2 shows interior-facing header tank 218 and exterior-facing header tank 220 of second bank radiator 214. In some configurations, each of the first bank radiators 206, 208, and 210 and each of the second bank radiators 212, 214, and 216 may have interior-facing and exterior-facing header tanks as shown for second bank radiator 214.

In some embodiments, each of the first bank 202 and second bank 204 radiators may be slightly canted with respect to the rail vehicle chassis, such that the exterior-facing header tank descends lower than the interior-facing header tank. This orientation allows the cooling fluid in the radiators to drain, for example.

In the embodiment illustrated in FIG. 2, cooling fluid is conducted into and out of each of the first bank 202 and second bank 204 radiators via one or more clamp-type couplings (e.g., couplings having a clamp mechanism) configured to join two segments of pipe. In one, non-limiting example, the clamp-type couplings referred to herein may be those manufactured by Victaulic Corporation of Easton, Pa. Accordingly, FIG. 2 shows clamp-type couplings 222 and 224 coupled to second bank radiator 214 and second bank radiators 212 and 216. Clamp-type couplings are shown in the radiator system 200 in various other locations as well. (Each clamp-type coupling is represented in the drawings using the same symbol, but not all of the clamp-type couplings are assigned reference numerals.) In particular, FIG. 2 shows clamp-type coupling 226 coupled to second bank radiator 212, and end cap 228 coupled to the clamp-type coupling 226. This structure may be used to prevent cooling fluid from flowing out of the radiator through clamp-type coupling 226 while preserving the modularity of the radiator configuration. End caps are shown coupled to various other couplings of the radiator system 200 as well. (Each end cap is represented in the drawings using the same symbol, but not all of the end caps are assigned reference numerals.)

As shown in FIG. 2, the first bank 202 of radiators has an unmodified, parallel configuration. Cooling fluid from the engine flows into the interior-facing header tanks of the first bank 202 of radiators. A different portion of cooling fluid flows from the interior-facing header tank of each of the first bank radiators 206, 208, and 210 and through each radiator to the exterior-facing header tank of each of the first bank radiators 206, 208, and 210. After flowing through the radiators, the cooling fluid exits the same end of the first bank 202 of radiators that it entered via a cooling fluid conduit coupled to the exterior-facing header tank of the radiator 210 and flowing in the opposite direction to the direction of cooling fluid flow into the first bank 202 of radiators. In this manner, cooling fluid which was heated by the engine is cooled by the first bank 202 radiators. The first bank 202 radiators may cool the cooling fluid to a temperature between 68° C. and 79° C., for example, such that engine reliability and emissions requirements are met.

The second bank 204 of radiators, on the other hand, has a modified, series configuration. Cooling fluid from the pump flows into the interior-facing header tank of the radiator 216. Because the portion of cooling fluid that enters the second bank 204 radiators has not passed through the engine immediately prior to entering the second bank 204 radiators, the cooling fluid may have a lower temperature than the portion of cooling fluid that enters the first bank 202 radiators.

As depicted, a blocking plate 230 is disposed in the cooling fluid conduit linking the interior-facing header tanks of second bank radiators 214 and 216. The blocking plate 230 may be any suitable flow stop disposed in the cooling fluid conduit linking the interior-facing header tanks of second bank radiators 214 and 216. Accordingly, the blocking plate 230 may be a circular plate having the same diameter as the conduit. In one embodiment, the blocking plate 230 may be inserted in the conduit and held in place by the clamp-type coupling 222 of the original radiator system. The second bank 204 further includes venting plates 232. The venting plates 232 may be any suitable flow restriction disposed in the cooling fluid conduit that connects the exterior-facing header tanks of second bank radiators 212 and 214 and in the cooling fluid conduit downstream of the exterior-facing header tank of the second bank radiator 216. Accordingly, each venting plate 232 may be a circular plate having the same diameter as the conduit, and comprising one or more relatively small holes to allow cooling fluid in the second bank radiators 212 and 214 to drain via the second bank radiator 216 when the engine is turned off. The holes may be small enough to ensure that the vast majority of cooling fluid is forced through the second bank 204 radiators in the illustrated zigzag pattern (e.g., “S” pattern) while the engine is running. When the engine is turned off or shutdown, the small holes in the venting plates 232 may allow the second bank 204 radiators to drain to the cooling fluid reservoir, for example. In one embodiment, the venting plate may be inserted in the conduit and held in place by the clamp-type coupling 224 of the original cooling system.

As described above, due to the blocking plate 230 and the venting plates 232, the cooling fluid flows through the second bank 204 radiators in a zigzag pattern. For example, cooling fluid flows from the pump outlet and into the interior-facing header tank of the second bank radiator 216 and through the radiator 216 to the exterior-facing header tank of the radiator 216. Next, the same portion of cooling fluid flows into the exterior-facing header tank of the radiator 214 and through the radiator 214 to the interior head tank of the radiator 214. Finally, the same portion of cooling fluid flows into the interior-facing header tank of the radiator 212 and through the radiator 212 to the exterior-facing header tank before exiting the second bank 204 of radiators at the opposite end of the second bank 204 and flowing in the same direction as cooling fluid flowing into the second bank 204 of radiators. Because the effective length of the second bank 204 is increased as a result of the zigzag flow path, the cooling fluid may be cooled to a temperature less than that of the cooling fluid that flows through the first bank 202.

In such a configuration, a flow speed of the fluid through the series flow path configuration may remain approximately the same as a flow speed of the fluid through the parallel flow path configuration, such that turbulence of the flow is not reduced and heat exchange of the second radiator system is maintained. Because the flow speed and turbulence of the cooling fluid flow is maintained, heat exchange of the cooling fluid through the second bank 204 radiators may be maintained when the second bank 204 radiators are modified. Moreover, since the effective length of the second bank 204 radiators is increased, cooling of the cooling fluid may be increased.

The radiator system 200 further includes a cooling fluid conduit 234 coupled to the outlet of the second bank 204 radiators which turns the cooling fluid flow by approximately 180 degrees. The cooling fluid conduit 234 may be coupled to the second bank 204 radiators via clamp-type coupling 224, as shown in FIG. 2. Further, the end of the cooling fluid conduit 234 which protrudes from the second bank 204 radiators and turns the cooling fluid flow 180° may be covered by a box 244 which protects the conduit 234 and reduces water damage to the second bank 204 radiators at the cooling fluid outlet. As depicted in FIG. 2, the cooling fluid conduit 234 runs underneath the second bank 204 radiators such that the cooling fluid flow flows away from the second bank 204 radiators at the same end as the cooling fluid enters the second bank 204 radiators. Thus, the cooling fluid outlet at an opposite end of the second bank 204 radiators from which the cooling fluid entered as the venting plates 232 allows the cooling fluid to exit the second bank 204 radiators, as the vast majority of cooling fluid is restricted from flowing to the cooling fluid reservoir via the exterior-facing header tank of the second bank radiator 216. In this manner, the cooling fluid may flow through the second bank 204 radiators in a zigzag path.

The cooling fluid conduit 234 carries the cooling fluid to an intercooler 236. As depicted in FIG. 2, replacement fittings 238 and 240 are coupled to the intercooler 236. The replacement fittings 238 and 240 may be used to allow the intercooler to accept cooling fluid from the second bank 204 of radiators and to deliver the cooling fluid to the inlet of the pump, respectively, for example. By directing the cooling fluid directly from the second bank 204 radiators to the intercooler 236, the cooling fluid that enters the intercooler 236 may be at a colder temperature, as the cooling fluid has not passed through the oil cooler before it flows to the intercooler 236. Further, because the second bank 204 radiators cool the cooling fluid to a temperature lower than the first bank 202 radiators cool the cooling fluid, the cooling fluid is at an even lower temperature when it enters the intercooler 236. In this manner, the manifold air temperature may be lowered by approximately 17° C. (30° F.) without reducing engine cooling fluid inlet temperatures. As a result, NO_(x) emissions may be reduced while engine operating efficiency is maintained.

In some embodiments, the radiator system may include one or more flow control devices (not shown) such as orifices or filters disposed in cooling fluid conduits. The flow control devices may be configured to provide desired flow rates through the various components of the cooling system. For example, the desired flow rates may be determined based on the size of the radiator banks, desired outlet temperature of the cooling fluid, and the like. In one non-limiting example, the flow control devices are configured such that flow rates through cooling system components are as follows: 600 gallons per minute (2271 liters per minute) through the engine, 150 gallons per minute (568 liters per minute) through the intercooler(s), 600 gallons per minute (2271 liters per minute) through the first bank of radiators, 150 gallons per minute (2271 liters per minute) through the second bank of radiators, 600 gallons per minute (2271 liters per minute) through the oil cooler, and 750 gallons per minute (2839 liters per minute) through the pump. In such an embodiment, the flow rate of cooling fluid through the first bank of radiators is greater than the flow rate of cooling fluid through the second bank of radiators. As such, the cooling fluid moves through the second bank of radiators more slowly than through the first bank of radiators resulting in greater cooling of the cooling fluid that passes through the second bank of radiators. In other embodiments, the flow control devices may be configured such that they may be controlled to vary the flow rate of the cooling during engine operation. For example, when greater cooling of the of the manifold air is desired, the flow rate of cooling fluid through the second bank of radiators may be reduced.

Further, in embodiments, the radiator system 200 is a fully flooded system. In a fully flooded system, the cooling fluid remains in the radiator system 200 during engine operation. When the engine is turned off, cooling fluid is drained from the first bank 202 radiators and the second bank 204 radiators to the cooling fluid reservoir. As such, the cooling system may include a shutter system in thermal communication with the radiator system 200. The shutter system may be controlled based on an ambient air temperature, for example, such that the shutters are closed when the ambient air temperature is less than a threshold temperature. In this way, the cooling system may be kept warm during cold ambient conditions and the radiator system is not drained when engine cooling is not desired.

FIGS. 3-5 show examples of an air flow control system 300 that may be used with a radiator system, such as the radiator system 200 described above with reference to FIG. 2. The air flow control system may include one or more shutter systems. For example, as shown in FIG. 1, each bank of radiators may have a corresponding shutter system. FIG. 3 shows a top-down view of the air flow control system 300 positioned over a radiator system. FIG. 4 shows a side view of the air flow control system 300 depicted in FIG. 3, and FIG. 5 shows a perspective view of the air flow control system 300.

As depicted in the top-down view of FIG. 3, the air flow control system 300 includes a first shutter system 302 and a second shutter system 304, each shutter system divided into three groups of shutters corresponding to a radiator in a radiator bank. For example, the first shutter system 302 includes shutter groups 306, 308, and 310 (first, second, and third groups) corresponding to first bank 202 radiators 210, 208, and 206, respectively, and the second shutter system 304 includes shutter groups 312, 314, and 316 (fourth, fifth, and sixth groups) corresponding to second bank 204 radiators 216, 214, and 212, respectively. In the embodiments described herein, each group of shutters includes a plurality of hinged panels that are interconnected for movement together. In other embodiments, the shutter system may include a single shutter, such as a door, or another controllable aperture.

As shown in FIG. 4, an air impeller 318, such as a radiator fan, is disposed below the first and second banks 202 and 204 of separate radiators. In such a configuration, the system is a push through system as the air impeller 318 pushes air through the radiators to the first and second shutter systems 302 and 304. In other embodiments, the system may be a pull through system in which one or more air impellers are disposed between the first and second shutter systems 302 and 304 and the first and second banks 202 and 204 of radiators. In the example shown, only one air impeller is included. In other examples, each bank of radiators may include one or more air impellers, for example. The air impeller 318 may be configured to provide a substantially equal airflow to each of the first bank 202 and second bank 204 radiators. In this way, the impeller 318 provides forced convection of ambient air such that heat transfer from the cooling fluid to the ambient air is assisted.

The air impeller 318 may be controlled by a controller, such as the controller 130 described above with reference to FIG. 1, based on an operating condition such as engine cooling fluid temperature or ambient air temperature, for example. In one example embodiment, the air impeller 318 is controlled responsive to the engine cooling fluid temperature (e.g., temperature of the cooling fluid which enters the engine). The set points, or thresholds, at which the air impeller 318 speed changes may be reduced in the modified cooling system in order to further reduce the temperature of the cooling fluid which flows from the second bank 204 radiators to the intercooler. For example, as the temperature of the engine cooling fluid increases, the air impeller 318 may be turned on to quarter speed when the engine cooling fluid reaches 77° C. (171° F.), to half speed when the engine cooling fluid reaches 79° C. (174° F.), and to full speed when the engine cooling fluid reaches 82° C. (179° F.). As the temperature of the engine cooling fluid decreases, the air impeller 318 may remain at full speed until the engine cooling fluid reaches 77° C. (170° F.), turned to half speed when the engine cooling fluid reaches 74° C. (165° F.), and turned to quarter speed when the engine cooling fluid reaches 73° C. (163° F.).

In the embodiment shown in FIG. 3, the first and second shutter systems 302 and 304 each include an actuator 320. In other embodiments, the air flow control system 300 may include a single actuator for all six groups of shutters 306, 308, 310, 312, 314, 316. As an example, the actuator 320 may be a spool valve or another suitable device that is configured to be operably coupled to an electronic control system, such as the controller 130 described above with reference to FIG. 1, for adjusting the position of the shutters. In some embodiments, the actuators 320 of the first and second shutter systems 302 and 304 may be controlled simultaneously such that the first and second shutter system 302 and 304 shutters are in substantially the same position. In other embodiments, the actuators of the first and second shutter systems 302 and 304 may be controlled individually such that shutters of the first shutter system 302 are in a different position than the shutters of the second shutter system 304. The actuators 320 may control the first group of shutters 306 and 312 in the first and second shutter systems 302 and 304, for example. Due to a linkage 322, such as a four bar linkage, mechanically coupled between each group of shutters in each shutter system, the shutters in each group may be adjusted to the same position. The linkage 322 is shown in the perspective view of FIG. 5.

The actuators 320 may be controlled by a controller, such as the controller 130 described above with reference to FIG. 1, based on an operating condition such as engine cooling fluid temperature or ambient air temperature, for example. In one example embodiment, the actuators 320 are controlled responsive to the engine cooling fluid temperature (e.g., temperature of the cooling fluid which enters the engine). The set points, or thresholds, at which the actuators 320 control the position of the shutters in the first and second shutter systems 302 and 304 may be reduced in the modified cooling system in order to further reduce the temperature of the cooling fluid which flows from the second radiator 204 bank to the intercooler. For example, as the temperature of the engine cooling fluid increases, the shutters may be opened when the engine cooling fluid reaches 76° C. (168° F.). As the temperature of the engine cooling fluid decreases, the shutters may be closed when the engine cooling fluid reaches 72° C. (161° F.). In some embodiments, the shutters may be opened and closed gradually or in steps such that the shutters may be partially open at particular set points. Further, in other embodiments, the first and second shutter systems 302 and 304 may be controlled independently. For example, the first shutter system 302 may have different set points than the shutter system 304 such that the shutters of the first shutter system 302 are opened at a higher temperature than the shutters of the second shutter system 304. In this way, greater cooling may be provided to the cooling fluid passing through the second bank 204 radiators such that the manifold air temperature may be further reduced.

In one embodiment, a kit for retrofitting an engine system having a cooling system including a first radiator system and a second radiator system comprises a plurality of blocking plates and venting plates configured to direct cooling fluid flow through the second radiator system along a non-parallel path. (For example, the blocking plates and venting plates may be adapted in size and shape for installation in the second radiator system, and configured such that subsequent installation and during operation of the second radiator system, the blocking plates and venting plates direct fluid flow through the second radiator system along a non-parallel path.) The kit further includes a first shutter system configured to couple to the first radiator system such that the first shutter system is in thermal communication with the first radiator system, and a second shutter system configured to couple to the second radiator system such that the second shutter system is in thermal communication with the second radiator system. The first and second shutter systems are configured to be operatively coupled to an electronic control system. The kit further comprises non-transitory, machine readable media embodying instructions that, when executed by the electronic control system, cause the electronic control system to adjust openings of the first and second shutter systems to control an outlet temperature of cooling fluid from the first and second radiator systems.

Continuing to FIG. 6, an example retrofit kit 600 is shown which modifies a cooling system such that a manifold temperature may be reduced, and thus NO_(x) emissions may be reduced, while maintaining a cooling fluid temperature of cooling fluid which enters an engine. The retrofit kit may enable a 17° C. (30° F.) reduction in manifold air temperature under most conditions, for example, without requiring a corresponding reduction in engine cooling fluid inlet temperatures. Further, the retrofit allows the reuse of most original cooling system components, requiring only a partial rerouting of the cooling fluid circuits, an addition of relatively inexpensive hardware, and a modification of the original cooling system control software.

As depicted in the example embodiment of FIG. 6, the retrofit kit 600 includes a blocking plate 230 configured to stop the flow of cooling fluid between header tanks of the second bank radiators, venting plates 232 configured to restrict the flow of cooling fluid between header tanks of the second bank of radiators, a cooling fluid conduit 234 configured to route cooling fluid from an outlet of the second bank of radiators to an inlet of an intercooler, and replacement fittings 238 and 240 configured to couple to the intercooler such that the intercooler can receive cooling fluid from the second bank radiators and deliver cooling fluid to the cooling fluid reservoir. The retrofit kit 600 further includes at least one shutter system configured to control a flow of air to the radiator system such that under selected conditions, the cooling system may be kept warm.

Further, as shown in FIG. 6, the retrofit kit 600 includes non-transitory, machine-readable media 602. The machine-readable media 602 embodies instructions which are executable by the control system, such as controller 130 described above with reference to FIG. 1. For example, when executed, the instructions cause the control system to adjust openings of the first and second shutter systems responsive to output from one or more sensors to control outlet temperatures of cooling fluid from the first and second radiator systems

It should be understood the retrofit kit is not limited to the components shown in the example of FIG. 6 and described above. In other examples, the retrofit kit may include additional or alternative components. As an example, the retrofit kit 600 may further include one or more flow control devices configured to provide desired flow rates through various components of the cooling system such as the first and second radiator banks, the intercooler, and the like. As another example, the retrofit kit 600 may include one or more sensors, such as cooling fluid sensors, manifold air temperature sensors, ambient air temperature sensors. altimeters, or the like.

FIG. 7 shows a flow chart illustrating a method 700 for operating an engine system, e.g., an engine system having a modified cooling system, such as the cooling system modified by retrofit kit 600 described above with reference to FIG. 6. Specifically, the method includes steps of determining an engine cooling fluid temperature and adjusting a degree (i.e., extent) to which the first and second shutter systems are open based on the cooling fluid temperature. In the example described with reference to FIG. 7, the first and second shutter systems are controlled simultaneously.

In other examples, the first and second shutter systems may be controlled individually such that cooling fluid outlet temperatures of the first and second radiator systems have an even greater difference or a lesser difference than when the shutters are controlled simultaneously. For example, if a manifold air temperature is below a threshold value, the second shutter system may be controlled to be closed while the first shutter system remains open such that the second radiator system provides less cooling to the charge-air intercooler. As another example, if the ambient air temperature is less than a threshold temperature but the manifold air temperature is greater than a threshold temperature, the first shutter system may be closed while the second shutter system is at least partially opened.

Continuing with FIG. 7, at step 702 operating conditions are determined. The operating conditions may include engine cooling fluid temperature, ambient air temperature, manifold air temperature, NO_(x) emission level, or the like.

At step 704, the engine cooling fluid temperature is determined. The engine cooling fluid temperature may be indicated by a temperature sensor disposed at a location upstream of the engine cooling fluid inlet (e.g., after the cooling exits the pump outlet and before the cooling fluid enters the engine).

Once the engine cooling fluid temperature is determined, it is determined if the engine cooling fluid temperature is greater than a first threshold temperature, at step 706. For example, when the cooling system is modified, the first threshold temperature may be reduced such that that cooling fluid that enters the one or more intercoolers may be cooled further by the second radiator system. In one example, the first threshold temperature may be approximately 76° C. (168° F.). In other examples, the first threshold temperature may be less than or greater than 76° C.

If it is determined that the engine cooling fluid temperature is greater than the first threshold temperature, the method proceeds to step 708 and the shutters are opened. In some examples, the shutters may have two positions: open and closed. In such an example, the shutters may be fully opened when it is determined that the engine cooling fluid temperature is greater than the first threshold temperature. In other examples, a degree (i.e., extent) to which the shutters are opened may depend upon the engine cooling fluid temperature and/or an air impeller (e.g., radiator fan) speed. For example, the shutters may be only partially opened (e.g., quarter open, half open, or the like) when the engine cooling fluid temperature exceeds the first threshold temperature. As another example, the shutters may be fully opened when the engine cooling fluid temperature exceeds the first threshold temperature and the air impeller is at quarter speed, and the shutters may be partially opened when the engine cooling fluid temperature exceeds the first threshold temperature and the impeller fan is at full speed.

By opening the shutters when the engine cooling fluid is greater than the first threshold temperature, the cooling capacity of the threshold temperature may be increased above the threshold temperature. In this manner, overheating of the engine system may be reduced. Further, because the cooling system is modified such that cooling fluid from the second radiator system is directed to one or more intercoolers, the manifold air temperature may be reduced in order to reduce NO_(x) emissions.

On the other hand, if it is determined that the engine cooling fluid temperature is less than the first threshold temperature, the method moves to step 710 and the current shutter positioned is maintained. For example, if the shutters are closed, the shutters remain closed. Likewise, if the shutters are already open, the shutters remain open to the degree (i.e., extent) to which they are open.

At step 712, it is determined if the engine cooling fluid temperature is less than a second threshold temperature. For example, when the cooling system is modified, the second threshold temperature may be reduced such that that cooling fluid that enters the one or more intercoolers may be cooled further by the second radiator system. In one example, the second threshold temperature may be approximately 72° C. (161° F.). In other examples, the first threshold temperature may be less than or greater than 72° C. If it is determined that the engine cooling fluid temperature is greater than the second threshold temperature, the method moves to step 716 and current shutter position is maintained. For example, if the shutters are currently open, the shutters remain open to the degree (i.e., extent) to which they are open. Likewise, if the shutters are currently closed, the shutters remain closed.

On the other hand, if it is determined that the engine cooling fluid temperature is less than the second threshold temperature, the method continues to step 714 and the shutters are closed. As stated above, in some examples, the shutters may have two positions: open and closed. In such an example, the shutters may be fully closed when it is determined that the engine cooling fluid temperature is less than the second threshold temperature. In other examples, a degree (i.e., extent) to which the shutters are closed may depend upon the engine cooling fluid temperature and/or an air impeller (e.g., radiator fan) speed. For example, the shutters may be only partially closed (e.g., quarter closed, half closed, or the like) when the engine cooling fluid temperature falls below the second threshold temperature. As another example, the shutters may be fully closed when the engine cooling fluid temperature falls below the second threshold temperature and the air impeller is at quarter speed, and the shutters may be only partially closed when the engine cooling fluid temperature falls below the second threshold temperature and the impeller fan is at full speed.

By closing the shutters when the engine cooling fluid temperature is less than the second threshold temperature, the cooling system, and thus the engine system, may be maintained at higher temperatures. Engine cooling fluid temperature may be less than the second threshold temperature during an engine start and/or when an ambient air temperature is relatively low, for example. Thus, by maintaining higher engine system and cooling system temperatures, the engine may be operated more efficiently for the current operating conditions.

As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. The terms “including” and “in which” are used as the plain-language equivalents of the respective terms “comprising” and “wherein.” Moreover, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements or a particular positional order on their objects.

This written description uses examples to disclose the invention, including the best mode, and also to enable a person of ordinary skill in the relevant art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

1. An apparatus forming at least a portion of a cooling circuit for a fluid source, comprising: a first radiator system having a parallel flow path configuration; a second radiator system having a series flow path configuration; at least one shutter system for adjusting airflow to one or more of the first radiator system or the second radiator system; and a controller configured to adjust operation of the shutter system responsive to an operating condition.
 2. The apparatus of claim 1, further comprising an intercooler in fluid communication with the second radiator system.
 3. The apparatus of claim 2, further comprising a cooling fluid reservoir in fluid communication with the first radiator system and the intercooler.
 4. The apparatus of claim 1, wherein the controller is further configured to receive a signal from a sensor and, responsive to the signal from the sensor, the controller is operable to control a degree to which the at least one shutter system is open.
 5. The apparatus of claim 4, wherein the sensor is a temperature sensor disposed in or proximate to a manifold such that the temperature sensor generates a signal indicative of a manifold air temperature as the operating condition.
 6. The apparatus of claim 5, wherein the temperature sensor is one of a plurality of temperature sensors, each of which is disposed in or proximate to a distinct manifold.
 7. The apparatus of claim 4, wherein the sensor is an engine cooling fluid temperature sensor, and the controller controls the degree to which the at least one shutter system is open, based at least in part on an engine cooling fluid temperature as the operating condition.
 8. The apparatus of claim 4, wherein the sensor is a temperature sensor that is disposed so as to determine an ambient temperature, and the controller controls the degree to which the at least one shutter system is open, based at least in part on the ambient temperature as the operating condition.
 9. A kit for retrofitting an engine system having a cooling system including a first radiator system and a second radiator system, comprising: a plurality of blocking plates and venting plates configured to direct cooling fluid flow through the second radiator system along a non-parallel path; a first shutter system configured to couple to the first radiator system such that the first shutter system is in thermal communication with the first radiator system, and a second shutter system configured to couple to the second radiator system such that the second shutter system is in thermal communication with the second radiator system, the first and second shutter systems configured to be operatively coupled to an electronic control system; and non-transitory, machine readable media embodying instructions that, when executed by the electronic control system, cause the electronic control system to adjust openings of the first and second shutter systems to control outlet temperatures of cooling fluid from the first and second radiator systems.
 10. The kit of claim 9, further including a manifold air temperature sensor, and the media further including instructions to adjust the openings of the first and second shutter systems responsive to output from the manifold air temperature sensor.
 11. The kit of claim 9, further including at least one cooling fluid conduit to route the cooling fluid flow from an outlet of the second radiator system to an intercooler and then to a cooling fluid reservoir.
 12. The kit of claim 9, further including an ambient air temperature sensor, and the media further including instructions to close the openings of the first and second shutter systems responsive to output from the ambient air temperature sensor indicating an ambient air temperature less than a threshold ambient air temperature.
 13. The kit of claim 9, wherein the plurality of blocking plates and venting plates comprises one blocking plate and two venting plates configured to couple to the second radiator system such that the non-parallel path has a zigzag pattern.
 14. The kit of claim 9, wherein the media include instructions for adjusting the openings of the first and second shutter systems to control the outlet temperature of cooling fluid from the second radiator system to less than the outlet temperature of cooling fluid from the first radiator system.
 15. The kit of claim 9, further comprising an engine cooling fluid temperature sensor, and the media further including instructions to adjust the openings of the first and second shutter systems responsive to output of the engine cooling fluid temperature sensor.
 16. A method for operating an engine system, comprising, based on at least one operating condition: directing a first portion of a cooling fluid from an engine through a first radiator system that has a parallel flow path configuration and from the first radiator system to a cooling fluid reservoir; directing a second portion of the cooling fluid from the engine through a second radiator system that has a series flow path configuration and from the second radiator system to an intercooler and then to the cooling fluid reservoir; and adjusting an opening of a first shutter system in thermal communication with the first radiator system and adjusting an opening of a second shutter system in thermal communication with the second radiator system such that an outlet temperature of the first portion of the cooling fluid from the first radiator system and an outlet temperature of the second portion of the cooling fluid from the second radiator system are adjusted.
 17. The method of claim 16, wherein the at least one operating condition is one or more of a manifold air temperature, an ambient air temperature, an engine emission level in an exhaust stream, or an engine cooling fluid temperature.
 18. The method of claim 16, wherein the first flow rate is greater than the second flow rate, and wherein the outlet temperature of the first portion of the cooling fluid from the first radiator system is greater than the outlet temperature of the second portion of the cooling fluid from the second radiator system.
 19. The method of claim 16, wherein the first radiator system and the second radiator system are fully flooded during engine operation.
 20. The method of claim 16, further comprising adjusting the opening of the first shutter system simultaneously with the opening of the second shutter system. 